Sept 15 (Reuters) - AT&T is evaluating a sale of its pay TV operations in Latin America as it seeks to pay down debt following its planned $85.4 billion acquisition of Time Warner Inc, people familiar with the matter said on Friday. AT&T is working with a financial adviser to field interest in the assets, which could be valued at more than $8 billion, the people added, asking not to be named because the matter is private.

Liberty Global PLC, Spanish telecommunications company Telefonica SA and Millicom International Cellular SA , a wireless player in Latin America, are some of the companies that could express interest in all or parts of AT&T's Latin American markets, according to the people.

AT&T declined to comment. Liberty Global, Telefonica and Millicom could not be reached for comment.

Most Latin American countries, with the exception of Venezuela, have stabilized over the past year with markets such as Brazil's rallying after struggling with a recession for several years following the end of a decades-long commodities boom.

There is no guarantee that AT&T will be successful in selling the business, which includes satellite and cable television services in Brazil, Colombia, Venezuela, Argentina and several other countries, the people said. It could still decide to keep the systems, the people added.

AT&T is not interested in selling its pay TV business in Mexico, since it has been investing in wireless services in the country, the sources said. It acquired these TV operations as part of its $49 billion acquisition of DirecTV in 2015.

AT&T has been reviewing its portfolio to find ways to help pay down its debt load, which will increase to about $180 million once its acquisition of Time Warner closes.

AT&T expects the Time Warner acquisition to close by the end of the year. The deal is currently under antitrust review by the U.S. Department of Justice.

AT&T's chief executive, Randall Stephenson, said earlier this week at a Goldman Sachs conference that every year the company "monetizes a number of assets that strategically don't fit and aren't in the longterm game plan of the business." The company has also said in the past that it would be open to a strategic combination in the region.

In the second quarter, AT&T had 13.6 million total subscribers in Latin America, excluding Mexico, and generated total revenue of $1.4 billion. AT&T owns about 93 percent of Sky Brasil, the largest satellite provider in the region's biggest economy. It owns PanAmericana, which offers satellite TV services under the DirecTV brand in countries including Venezuela, Argentina, Chile, Colombia and Puerto Rico.

AT&T has also been looking to sell its Digital Life home security business, which could fetch close to $1 billion in a sale, Reuters previously reported. (Reporting by Liana B. Baker and Jessica Toonkel in New York; Editing by Leslie Adler)